1 /*
2 * SPEAr Keyboard Driver
3 * Based on omap-keypad driver
4 *
5 * Copyright (C) 2010 ST Microelectronics
6 * Rajeev Kumar<rajeev-dlh.kumar@st.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #include <linux/clk.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/input.h>
18 #include <linux/io.h>
19 #include <linux/irq.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_wakeup.h>
25 #include <linux/slab.h>
26 #include <linux/types.h>
27 #include <linux/platform_data/keyboard-spear.h>
28
29 /* Keyboard Registers */
30 #define MODE_CTL_REG 0x00
31 #define STATUS_REG 0x0C
32 #define DATA_REG 0x10
33 #define INTR_MASK 0x54
34
35 /* Register Values */
36 #define NUM_ROWS 16
37 #define NUM_COLS 16
38 #define MODE_CTL_PCLK_FREQ_SHIFT 9
39 #define MODE_CTL_PCLK_FREQ_MSK 0x7F
40
41 #define MODE_CTL_KEYBOARD (0x2 << 0)
42 #define MODE_CTL_SCAN_RATE_10 (0x0 << 2)
43 #define MODE_CTL_SCAN_RATE_20 (0x1 << 2)
44 #define MODE_CTL_SCAN_RATE_40 (0x2 << 2)
45 #define MODE_CTL_SCAN_RATE_80 (0x3 << 2)
46 #define MODE_CTL_KEYNUM_SHIFT 6
47 #define MODE_CTL_START_SCAN (0x1 << 8)
48
49 #define STATUS_DATA_AVAIL (0x1 << 1)
50
51 #define DATA_ROW_MASK 0xF0
52 #define DATA_COLUMN_MASK 0x0F
53
54 #define ROW_SHIFT 4
55
56 struct spear_kbd {
57 struct input_dev *input;
58 void __iomem *io_base;
59 struct clk *clk;
60 unsigned int irq;
61 unsigned int mode;
62 unsigned int suspended_rate;
63 unsigned short last_key;
64 unsigned short keycodes[NUM_ROWS * NUM_COLS];
65 bool rep;
66 bool irq_wake_enabled;
67 u32 mode_ctl_reg;
68 };
69
spear_kbd_interrupt(int irq,void * dev_id)70 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
71 {
72 struct spear_kbd *kbd = dev_id;
73 struct input_dev *input = kbd->input;
74 unsigned int key;
75 u32 sts, val;
76
77 sts = readl_relaxed(kbd->io_base + STATUS_REG);
78 if (!(sts & STATUS_DATA_AVAIL))
79 return IRQ_NONE;
80
81 if (kbd->last_key != KEY_RESERVED) {
82 input_report_key(input, kbd->last_key, 0);
83 kbd->last_key = KEY_RESERVED;
84 }
85
86 /* following reads active (row, col) pair */
87 val = readl_relaxed(kbd->io_base + DATA_REG) &
88 (DATA_ROW_MASK | DATA_COLUMN_MASK);
89 key = kbd->keycodes[val];
90
91 input_event(input, EV_MSC, MSC_SCAN, val);
92 input_report_key(input, key, 1);
93 input_sync(input);
94
95 kbd->last_key = key;
96
97 /* clear interrupt */
98 writel_relaxed(0, kbd->io_base + STATUS_REG);
99
100 return IRQ_HANDLED;
101 }
102
spear_kbd_open(struct input_dev * dev)103 static int spear_kbd_open(struct input_dev *dev)
104 {
105 struct spear_kbd *kbd = input_get_drvdata(dev);
106 int error;
107 u32 val;
108
109 kbd->last_key = KEY_RESERVED;
110
111 error = clk_enable(kbd->clk);
112 if (error)
113 return error;
114
115 /* keyboard rate to be programmed is input clock (in MHz) - 1 */
116 val = clk_get_rate(kbd->clk) / 1000000 - 1;
117 val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
118
119 /* program keyboard */
120 val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
121 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
122 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
123 writel_relaxed(1, kbd->io_base + STATUS_REG);
124
125 /* start key scan */
126 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
127 val |= MODE_CTL_START_SCAN;
128 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
129
130 return 0;
131 }
132
spear_kbd_close(struct input_dev * dev)133 static void spear_kbd_close(struct input_dev *dev)
134 {
135 struct spear_kbd *kbd = input_get_drvdata(dev);
136 u32 val;
137
138 /* stop key scan */
139 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
140 val &= ~MODE_CTL_START_SCAN;
141 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
142
143 clk_disable(kbd->clk);
144
145 kbd->last_key = KEY_RESERVED;
146 }
147
148 #ifdef CONFIG_OF
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)149 static int spear_kbd_parse_dt(struct platform_device *pdev,
150 struct spear_kbd *kbd)
151 {
152 struct device_node *np = pdev->dev.of_node;
153 int error;
154 u32 val, suspended_rate;
155
156 if (!np) {
157 dev_err(&pdev->dev, "Missing DT data\n");
158 return -EINVAL;
159 }
160
161 if (of_property_read_bool(np, "autorepeat"))
162 kbd->rep = true;
163
164 if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
165 kbd->suspended_rate = suspended_rate;
166
167 error = of_property_read_u32(np, "st,mode", &val);
168 if (error) {
169 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
170 return error;
171 }
172
173 kbd->mode = val;
174 return 0;
175 }
176 #else
spear_kbd_parse_dt(struct platform_device * pdev,struct spear_kbd * kbd)177 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
178 struct spear_kbd *kbd)
179 {
180 return -ENOSYS;
181 }
182 #endif
183
spear_kbd_probe(struct platform_device * pdev)184 static int spear_kbd_probe(struct platform_device *pdev)
185 {
186 struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
187 const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
188 struct spear_kbd *kbd;
189 struct input_dev *input_dev;
190 struct resource *res;
191 int irq;
192 int error;
193
194 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
195 if (!res) {
196 dev_err(&pdev->dev, "no keyboard resource defined\n");
197 return -EBUSY;
198 }
199
200 irq = platform_get_irq(pdev, 0);
201 if (irq < 0) {
202 dev_err(&pdev->dev, "not able to get irq for the device\n");
203 return irq;
204 }
205
206 kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
207 if (!kbd) {
208 dev_err(&pdev->dev, "not enough memory for driver data\n");
209 return -ENOMEM;
210 }
211
212 input_dev = devm_input_allocate_device(&pdev->dev);
213 if (!input_dev) {
214 dev_err(&pdev->dev, "unable to allocate input device\n");
215 return -ENOMEM;
216 }
217
218 kbd->input = input_dev;
219 kbd->irq = irq;
220
221 if (!pdata) {
222 error = spear_kbd_parse_dt(pdev, kbd);
223 if (error)
224 return error;
225 } else {
226 kbd->mode = pdata->mode;
227 kbd->rep = pdata->rep;
228 kbd->suspended_rate = pdata->suspended_rate;
229 }
230
231 kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
232 if (IS_ERR(kbd->io_base))
233 return PTR_ERR(kbd->io_base);
234
235 kbd->clk = devm_clk_get(&pdev->dev, NULL);
236 if (IS_ERR(kbd->clk))
237 return PTR_ERR(kbd->clk);
238
239 input_dev->name = "Spear Keyboard";
240 input_dev->phys = "keyboard/input0";
241 input_dev->id.bustype = BUS_HOST;
242 input_dev->id.vendor = 0x0001;
243 input_dev->id.product = 0x0001;
244 input_dev->id.version = 0x0100;
245 input_dev->open = spear_kbd_open;
246 input_dev->close = spear_kbd_close;
247
248 error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
249 kbd->keycodes, input_dev);
250 if (error) {
251 dev_err(&pdev->dev, "Failed to build keymap\n");
252 return error;
253 }
254
255 if (kbd->rep)
256 __set_bit(EV_REP, input_dev->evbit);
257 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
258
259 input_set_drvdata(input_dev, kbd);
260
261 error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
262 "keyboard", kbd);
263 if (error) {
264 dev_err(&pdev->dev, "request_irq failed\n");
265 return error;
266 }
267
268 error = clk_prepare(kbd->clk);
269 if (error)
270 return error;
271
272 error = input_register_device(input_dev);
273 if (error) {
274 dev_err(&pdev->dev, "Unable to register keyboard device\n");
275 clk_unprepare(kbd->clk);
276 return error;
277 }
278
279 device_init_wakeup(&pdev->dev, 1);
280 platform_set_drvdata(pdev, kbd);
281
282 return 0;
283 }
284
spear_kbd_remove(struct platform_device * pdev)285 static int spear_kbd_remove(struct platform_device *pdev)
286 {
287 struct spear_kbd *kbd = platform_get_drvdata(pdev);
288
289 input_unregister_device(kbd->input);
290 clk_unprepare(kbd->clk);
291
292 device_init_wakeup(&pdev->dev, 0);
293 platform_set_drvdata(pdev, NULL);
294
295 return 0;
296 }
297
298 #ifdef CONFIG_PM
spear_kbd_suspend(struct device * dev)299 static int spear_kbd_suspend(struct device *dev)
300 {
301 struct platform_device *pdev = to_platform_device(dev);
302 struct spear_kbd *kbd = platform_get_drvdata(pdev);
303 struct input_dev *input_dev = kbd->input;
304 unsigned int rate = 0, mode_ctl_reg, val;
305
306 mutex_lock(&input_dev->mutex);
307
308 /* explicitly enable clock as we may program device */
309 clk_enable(kbd->clk);
310
311 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
312
313 if (device_may_wakeup(&pdev->dev)) {
314 if (!enable_irq_wake(kbd->irq))
315 kbd->irq_wake_enabled = true;
316
317 /*
318 * reprogram the keyboard operating frequency as on some
319 * platform it may change during system suspended
320 */
321 if (kbd->suspended_rate)
322 rate = kbd->suspended_rate / 1000000 - 1;
323 else
324 rate = clk_get_rate(kbd->clk) / 1000000 - 1;
325
326 val = mode_ctl_reg &
327 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
328 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
329 << MODE_CTL_PCLK_FREQ_SHIFT;
330 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
331
332 } else {
333 if (input_dev->users) {
334 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
335 kbd->io_base + MODE_CTL_REG);
336 clk_disable(kbd->clk);
337 }
338 }
339
340 /* store current configuration */
341 if (input_dev->users)
342 kbd->mode_ctl_reg = mode_ctl_reg;
343
344 /* restore previous clk state */
345 clk_disable(kbd->clk);
346
347 mutex_unlock(&input_dev->mutex);
348
349 return 0;
350 }
351
spear_kbd_resume(struct device * dev)352 static int spear_kbd_resume(struct device *dev)
353 {
354 struct platform_device *pdev = to_platform_device(dev);
355 struct spear_kbd *kbd = platform_get_drvdata(pdev);
356 struct input_dev *input_dev = kbd->input;
357
358 mutex_lock(&input_dev->mutex);
359
360 if (device_may_wakeup(&pdev->dev)) {
361 if (kbd->irq_wake_enabled) {
362 kbd->irq_wake_enabled = false;
363 disable_irq_wake(kbd->irq);
364 }
365 } else {
366 if (input_dev->users)
367 clk_enable(kbd->clk);
368 }
369
370 /* restore current configuration */
371 if (input_dev->users)
372 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
373
374 mutex_unlock(&input_dev->mutex);
375
376 return 0;
377 }
378 #endif
379
380 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
381
382 #ifdef CONFIG_OF
383 static const struct of_device_id spear_kbd_id_table[] = {
384 { .compatible = "st,spear300-kbd" },
385 {}
386 };
387 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
388 #endif
389
390 static struct platform_driver spear_kbd_driver = {
391 .probe = spear_kbd_probe,
392 .remove = spear_kbd_remove,
393 .driver = {
394 .name = "keyboard",
395 .owner = THIS_MODULE,
396 .pm = &spear_kbd_pm_ops,
397 .of_match_table = of_match_ptr(spear_kbd_id_table),
398 },
399 };
400 module_platform_driver(spear_kbd_driver);
401
402 MODULE_AUTHOR("Rajeev Kumar");
403 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
404 MODULE_LICENSE("GPL");
405